This Committee sat for nearly two years, at the end of which it made a report to the Government, which fills a very large volume, in which are detailed an immense number of experiments, touching the form and size of cables, their relative strength and flexibility, the power of telegraphing at long distances, the speed at which messages could be sent; and in fine, every possible question, either as to the electrical or engineering difficulties to be overcome. The result of these manifold and laborious experiments is summed up in the following certificate, signed by all who had taken part in this memorable investigation: "London, 13th July, 1863. "We, the undersigned, members of the Committee, who were appointed by the Board of Trade, in 1859, to investigate the question of submarine telegraphy, and whose investigation continued from that time to April, 1861, do hereby state, as the result of our deliberations, that a well-insulated cable, properly protected, of suitable specific gravity, made with care, and tested under water throughout its progress with the best known apparatus, and paid into the ocean with the most improved machinery, possesses every prospect of not only being successfully laid in the first instance, but may reasonably be relied upon to continue for many years in an efficient state for the transmission of signals. Douglas Galton, C. Wheatstone, Wm. Fairbairn, Geo. P. Bidder, Cromwell F. Varley, Latimer Clark, Edwin Clark, Geo. Saward." Thus the years which followed the failure of 1858--though they saw no attempt to lay another ocean cable--were not years of idleness. They were rather years of experiment and of preparation, clearing the way for new efforts and final victory. The Atlantic Telegraph itself had been a grand experiment. It had taught many important truths which could be learned in no other way. Not only had it demonstrated the possibility of telegraphing from continent to continent, but it had been useful even in exposing its own defects, as it taught how to avoid them in the future.